springboot mybatis-plus 使用
创建springboot环境，略过
pom文件导入依赖
application.properties文件进行配置
#datasource spring.datasource.driver-class-name=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/mp?characterEncoding=UTF-8&useUnicode=true spring.datasource.username=root spring.datasource.password=root spring.datasource.type=com.alibaba.druid.pool.DruidDataSource #mybatis-plus mybatis-plus.config-location=classpath:mybatis/mybatis-config.xml mybatis-plus.mapper-locations=classpath:mybatis/mappers/*.xml #ExecutorType.SIMPLE：该执行器类型不做特殊的事情， # 为每个语句的执行创建一个新的预处理语句（PreparedStatement） #ExecutorType.REUSE：该执行器类型会复用预处理语句（PreparedStatement） #ExecutorType.BATCH：该执行器类型会批量执行所有的更新语句 mybatis-plus.executor-type=simple
其他配置信息看官网 http://mp.baomidou.com/guide/
代码生成器
@Test
public void contextLoads() {
//1. 全局配置
GlobalConfig config = new GlobalConfig();
config.setActiveRecord(true) // 是否支持AR模式
.setAuthor("lee-suoer") // 作者
.setOutputDir("D:\\Users\\Administrator\\IdeaProjects\\mybatisplus\\src\\main\\java") // 生成路径
.setFileOverride(true) // 文件覆盖
.setIdType(IdType.AUTO) // 主键策略
//不已I开头
.setServiceName("%sService") // 设置生成的service接口的名字的首字母是否为I
// IEmployeeService
.setBaseResultMap(true)
.setBaseColumnList(true);
//2. 数据源配置
DataSourceConfig dsConfig = new DataSourceConfig();
dsConfig.setDbType(DbType.MYSQL) // 设置数据库类型
.setDriverName("com.mysql.jdbc.Driver")
.setUrl("jdbc:mysql://localhost:3306/mp")
.setUsername("root")
.setPassword("root");
//3. 策略配置
StrategyConfig stConfig = new StrategyConfig();
stConfig.setCapitalMode(true) //全局大写命名
.setNaming(NamingStrategy.underline_to_camel) // 数据库表映射到实体的命名策略
.setTablePrefix("tbl_")
.setInclude("tbl_employee"); // 生成的表
//4. 包名策略配置
PackageConfig pkConfig = new PackageConfig();
// 各种文件生成的位置
pkConfig.setParent("com.example.mybatisplus")
.setMapper("mapper")
.setService("service")
.setController("controller")
.setEntity("entity")
.setXml("mapper");
//5. 整合配置
AutoGenerator ag = new AutoGenerator();
ag.setGlobalConfig(config)
.setDataSource(dsConfig)
.setStrategy(stConfig)
.setPackageInfo(pkConfig);
//6. 执行
ag.execute();
}
运行之后生成文件
可以将mapper.xml放入准备好的文件夹，便于管理
实体类
dao接口
service
自动注入了mapper
通用crud
自带的serviceImpl已经为我们注入了basemapper，我们不需要手动注入mapper了，直接使用。
public void insert() {
//初始化Employee对象
Employee employee = new Employee();
employee.setLastName("MP");
employee.setEmail("[email protected]");
employee.setGender("1");
employee.setAge(22);
Integer result = baseMapper.insert(employee);
System.out.println("result: " + result );
//获取当前数据在数据库中的主键值
Integer key = employee.getId();
System.out.println("key:" + key );
}
public void delete() {
// 1 .根据id进行删除
Integer result = baseMapper.deleteById(13);
System.out.println("result: " + result );
//2. 根据 条件进行删除
// Map<String,Object> columnMap = new HashMap<>();
// columnMap.put("last_name", "MP");
// columnMap.put("email", "[email protected]");
// Integer result = baseMapper.deleteByMap(columnMap);
// System.out.println("result: " + result );
//3. 批量删除
// List<Integer> idList = new ArrayList<>();
// idList.add(3);
// idList.add(4);
// idList.add(5);
// Integer result = baseMapper.deleteBatchIds(idList);
// System.out.println("result: " + result );
4.包装条件
baseMapper.delete(new QueryWrapper<Employee>().eq("last_name", "MP"));
}
public void update() {
//初始化修改对象
Employee employee = new Employee();
employee.setId(7);
employee.setLastName("aa");
employee.setEmail("[email protected]");
employee.setGender("0");
//employee.setAge(33);
Integer result = baseMapper.updateById(employee);
baseMapper.update(employee,new UpdateWrapper<Employee>()
.eq("last_name", "Tom")
.eq("age", 44));
System.out.println("result: " + result );
}
public void select() {
//1. 通过id查询
Employee employee = baseMapper.selectById(7);
System.out.println(employee);
//2. 通过多个列进行查询 id + lastName
// Employee employee = new Employee();
// employee.setId(7);
// employee.setLastName("ssss");
// employee.setGender("0");
// Employee result = baseMapper.selectOne(employee);
// System.out.println("result: " +result );
//3. 通过多个id进行查询 <foreach>
// List<Integer> idList = new ArrayList<>();
// idList.add(4);
// idList.add(5);
// idList.add(6);
// idList.add(7);
// List<Employee> emps = baseMapper.selectBatchIds(idList);
// System.out.println(emps);
//4. 通过Map封装条件查询
// Map<String,Object> columnMap = new HashMap();
// columnMap.put("last_name", "Tom");
// columnMap.put("gender", 1);
// List<Employee> emps = baseMapper.selectByMap(columnMap);
// System.out.println(emps);
//5. 分页查询
IPage<Employee> page = baseMapper.selectPage(new Page<Employee>(3, 2), null);
System.out.println(page.getRecords());
}
AR操作
public void ARdelete() {
Employee employee = new Employee();
boolean result = employee.deleteById(2);
// employee.setId(2);
// boolean result = employee.deleteById();
// System.out.println("result:" +result );
boolean result = employee.delete(new QueryWrapper<Employee>().like("last_name", "小"));
System.out.println(result );
}
public void ARselect() {
Employee employee = new Employee();
//Employee result = employee.selectById(14);
// employee.setId(14);
// Employee result = employee.selectById();
// System.out.println(result );
// List<Employee> emps = employee.selectAll();
// System.out.println(emps);
// List<Employee > emps=
// employee.selectList(new QueryWrapper<Employee>().like("last_name", "老师"));
// System.out.println(emps);
Integer result = employee.selectCount(new QueryWrapper<Employee>().eq("gender", 0));
System.out.println("result: " +result );
}
public void ARinsert() {
Employee employee = new Employee();
employee.setLastName("sdsds");
employee.setEmail("[email protected]");
employee.setGender("1");
employee.setAge(35);
boolean result = employee.insert();
System.out.println("result:" +result );
}
public void ARupdate() {
Employee employee = new Employee();
employee.setId(20);
employee.setLastName("as");
employee.setEmail("[email protected]");
employee.setGender("1");
employee.setAge(36);
boolean result = employee.updateById();
System.out.println("result:" +result );
employee.update(new QueryWrapper<Employee>().eq("last_name","dsad"));
}
逻辑删除
实体类注解标注
application.properties
添加配置类
性能分析
添加一个插件
乐观锁
对应的表字段加注解
配置类